Headache features of cerebellar ischemic strokes: Clinical and radiological-experiences of a single center.

The prevalence of headache in stroke has been reported between 8% and 34%. Determining the prevalence, features, and effects on prognosis of cerebellar ischemic strokes that presented with headache solely and/or with other cerebellar signs were the aims of our study.All patients diagnosed with cerebellar ischemia were included. Electronic medical records were reviewed. Patients have been followed up for 6th month. Descriptive statistics were generated. A total of 4763 patients were evaluated retrospectively, 200 patients had cerebellar ischemia and 22 patients of these cerebellar ischemias (11%) had a headache at initial presentation. Ataxia, dysarthria, dysmetria were the most common neurological findings. There was no significant difference whether ischemic lesion single or multiple and whether above or below 1.5 cm diameter. Ischemic lesions generally were in cortical/ juxtacortical layer. According to vascular perfusion areas, 54.5% patients' ischemia was located in PICA (posterior inferior cerebellar artery) territory. Patients presenting with a headache, predominantly had left hemispheric (vermian > hemispheric > pedincular) involvement. Although these patients generally had high modified Rankin Scale scores at the first evaluation, they had low NIHSS (National Institutes of Health Stroke Scale) scores (0-5), and nearly all patients recovered, with low mRS at the 6-month follow-up.Cerebellar ischemic strokes with headache presentation are significantly prevalent in patients with left hemispheric, cortical/juxtacortical, PICA perfusion territory ischemias and are associated with low morbidity unless there was a conscious disorder. We believe this is one of the first studies that evaluated the clinical and radiological parameters of cerebellar stroke patients with headache.

Voluntary movement reverses the effect of cathodal transcranial direct current stimulation (tDCS) on corticomotor excitability.

Motor cortex activity level is a critical part of the effect of transcranial direct current stimulation (tDCS) on corticomotor excitability. Based on homeostatic plasticity, the state of the stimulated cortical area influences the direction of neuroplastic changes induced by stimuli. Owing to homeostatic plasticity, cathodal tDCS (c-tDCS) would likely have a pronounced inhibitory effect on corticomotor excitability during a motor task, compared with the resting state. To test this hypothesis, we detected motor evoked potential (MEP) amplitude changes before and during c-tDCS with voluntary movement. Twelve healthy right-handed volunteers (9 males, 27-48 years) were enrolled in the study. Subjects performed little finger abduction motor task. Passive (APB) and active (ADM) muscles were studied. MEP amplitudes were measured during resting (baseline) and movement stages, and subsequently with the contralateral M1 modulated by c-tDCS. c-tDCS caused reduced baseline MEP amplitude in the ADM (p < 0.05) and APB (p < 0.001) muscles. Sham stimulation had no effect on the baseline MEP amplitudes. MEP amplitude ratio (MEP amplitude triggered by movement/baseline MEP amplitude) was higher during c-tDCS than before c-tDCS (p < 0.01). Our results suggested that during voluntary contraction, c-tDCS has an opposite effect on corticospinal excitability compared with resting state modulation effect. This contrast effect could be related to modulation of movement preparation and execution.